With children from the Bellevue Family YMCA demonstrating the energy savings compact fluorescent light bulbs can generate Friday, Puget Sound Energy will launch its "Rock the Bulb" campaign to give away 400,000 free bulbs around Western Washington this summer and fall.

A Rock the Bulb exchange is set for this Saturday and Sunday, 10 a.m. to 4 p.m., at the Lowe's in Bellevue, 11959 Northup Way.

Compact fluorescent bulbs can use up to 75 percent less energy and last up to 10 times longer than incandescent ones. At a media event at the Lowe's store in Bellevue, the children will pedal a "power bike" and use a hand crank to illustrate that difference in power needed.

For Rock the Bulb, PSE will appear to Lowe's or Ace Hardware stores in cities over the next 15 weekends, through Oct. 31. On those weekends, PSE will hand out free compact fluorescent bulbs in exchange for incandescent bulbs, with a limit of 10 to a customer. CFL bulbs now come in a variety of shapes and sizes for almost any lighting fixture.

Each household that switches from incandescent bulbs to compact fluorescents saves energy and money. The cut in energy usage collectively across the state would benefit the environment in a big way.

Following the media demonstration, PSE and volunteers with nonprofit partner Project Porchlight will go door-to-door in a Bellevue neighborhood to distribute free CFL bulbs to residents.

All of PSE's Rock the Bulb Tour -- Unplugged events, will be 10 a.m. to 4 p.m. on Saturdays and Sundays.